Peanut Butter Cookie Bars are my go-to when I want the taste of a classic peanut butter cookie but in an easy pan-baked bar. They’re soft and chewy, with that rich peanut butter flavor that stays front and center.
I like this version because it bakes up with set edges and a tender middle, so you don’t end up with dry bars. Chocolate chips are optional, but I think the mix of peanut butter + semisweet chocolate is hard to beat.
These are especially good for cookie trays, casual get-togethers, and weekend baking when I’d rather slice bars than scoop individual cookies. A little flaky salt on top is a small extra step that makes a difference.
Why You’ll Love This Recipe
Soft and Chewy: The texture is what I want from a peanut butter cookie bar—tender in the center with edges that still have a little bite.
One Pan: No cookie sheets, no multiple batches. You spread it in a pan, bake once, and slice.
Classic Peanut Butter Flavor: This tastes like a real peanut butter cookie, not just “sweet bar” with a hint of peanut butter.
Chocolate Chip Option: Add chips for a little extra sweetness and that peanut butter-and-chocolate thing that always works.
Easy to Slice and Serve: These travel well and stack nicely for bake sales, potlucks, and holiday platters.
Ingredients You’ll Need
Dry
- All-purpose flour: I use regular flour here. It gives the bars structure so they slice cleanly once they’re cool.
- Baking powder: Helps the bars lift a little so they don’t bake up heavy.
- Baking soda: This is what gives you that classic cookie texture and helps the edges set.
- Fine salt: Don’t skip it. Peanut butter desserts taste flat without salt.
Wet
- Unsalted butter: Softened butter creams better, which helps the bars bake up lighter instead of dense.
- Creamy peanut butter: I stick with creamy for a smooth, even crumb. Natural peanut butter can work, but it needs to be really well mixed and not super oily.
- Light brown sugar: This is where a lot of the chew comes from. Dark brown sugar works too if that’s what you have.
- Granulated sugar: Adds sweetness and helps the edges get that lightly crisp cookie-bar finish.
- Eggs: Room temp is best so everything blends quickly and evenly.
- Vanilla extract: It rounds out the peanut butter flavor and makes the bars taste more like a cookie.
Mix ins and topping
- Semi-sweet chocolate chips: Semisweet is my go-to here. Milk chocolate is fine if you want it sweeter.
- Flaky salt: Totally optional, but a little sprinkle on top is really nice, especially if you use chocolate chips.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Line a 9×13-inch pan with parchment paper and lightly grease it.
- Mix the dry ingredients: Whisk the flour, baking powder, baking soda, and salt together in a medium bowl. Set aside.
- Beat the butter and peanut butter: In a large bowl, beat the softened butter and creamy peanut butter until smooth.
- Add the sugars: Beat in the brown sugar and granulated sugar until the mixture looks fluffy and well blended.
- Add the eggs and vanilla: Beat in the eggs, then add the vanilla, mixing until smooth.
- Add the dry ingredients: Mix in the dry ingredients just until you no longer see dry flour. Don’t overmix.
- Fold in the chocolate chips: If using, fold in the chocolate chips until they’re evenly mixed through the batter.
- Spread the batter: Scrape the batter into the prepared pan and spread it into an even layer, all the way into the corners.
- Bake: Bake for 22 to 28 minutes, until the edges are set and the center is just set. A toothpick should come out with a few moist crumbs.
- Let cool: Cool completely in the pan before slicing. This makes the bars much easier to cut cleanly.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Don’t overbake them. Pull the pan when the center looks just set and a toothpick shows a few moist crumbs. If you bake until the toothpick is totally clean, the bars can dry out fast.
Use natural peanut butter only if it’s well mixed. If there’s a thick layer of oil on top, stir it in really well first. Overly oily peanut butter can make the bars bake up a little greasy.
Line the pan with parchment. It keeps the bars from sticking and makes it easy to lift the whole slab out for neater slicing.
Try a smaller pan for thicker bars. A 9×9-inch pan gives you taller, thicker cookie bars, but you’ll need a longer bake time.
Let them cool all the way before cutting. Warm bars are delicious, but they’ll crumble more. For clean squares, wait until they’re fully cool.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Milk: A cold glass of milk is classic with peanut butter bars. I like it even more if you add a little flaky salt on top.
- Coffee or espresso: These are really good with coffee, especially in the afternoon. A latte or iced coffee works great too.
- Ice cream: Serve a bar with vanilla ice cream on the side if you want a simple plated dessert. Chocolate or peanut butter ice cream is great here too.
- Fruit: Fresh strawberries or raspberries are nice on the side. It’s an easy way to add something fresh to the plate.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store baked bars airtight at room temperature for up to 4 days. I usually keep them in a covered container with parchment between layers so they don’t stick.
If you want to make them ahead for a party, bake them the day before and slice once fully cool. The texture actually holds up really well overnight.
For longer storage, you can freeze the bars (whole or sliced) for up to 2 months. Let them thaw at room temperature before serving.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
Can I use natural peanut butter?
You can, as long as it’s well mixed and not overly oily. If it’s separated and runny, it can change the texture and make the bars a little greasy.
How do I know when the bars are done?
Look for edges that are set and lightly browned, with a center that looks just set. A toothpick should come out with a few moist crumbs, not wet batter.
Can I bake these in a 9×9-inch pan?
Yes, that’s a good option if you want thicker bars. Plan on baking about 28 to 35 minutes, and still use the “just set” look as your doneness cue.
What can I use instead of chocolate chips?
Peanut butter chips are great if you want even more peanut butter flavor. Chopped peanuts also work well if you want some crunch.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Peanut Butter Cookie Bars
INGREDIENTS
Dry
- 2 cups all purpose flour
- 1 tsp baking powder
- 1 tsp baking soda
- ½ tsp fine salt.
Wet
- ¾ cup unsalted butter softened
- ¾ cup creamy peanut butter
- 1 cup light brown sugar packed
- ½ cup granulated sugar
- 2 large eggs room temperature
- 2 tsp vanilla extract.
Mix ins and topping
- 1 cup semi sweet chocolate chips
- flaky salt for topping optional.
INSTRUCTIONS
Prep
- heat oven to 350F
- line a 9x13 inch pan with parchment and lightly grease.
Mix and bake
- whisk flour baking powder baking soda and salt
- beat butter peanut butter brown sugar and granulated sugar until fluffy
- beat in eggs and vanilla until smooth
- mix in dry ingredients just until combined
- fold in chocolate chips if using
- spread batter evenly in pan
- bake until edges are set and center is just set and a toothpick shows a few moist crumbs 22 to 28 minutes
- cool completely before slicing for clean bars.
